What Does Additive Effects Mean?
Additive effects are the resulting effect of two or more agents acting together. It is the sum of the effects of the individual agents. In relation to chemicals, additive effects are the sum of the effects of two chemicals when mixed together. Chemicals with similar chemical structures are usually combined, with no adverse effects resulting.
The sum of the additive effects are what you would be expect if you were exposed to each of the chemicals individually. Often, however there are synergistic effects, in which case, the combined effects are greater than each chemical by themselves.